Steemit now offers the options to promote a post by giving away some of your funds. This post details how to do it. You send funds to a special account and that will allow the post to show on the promoted page. I don't think anyone gets that money.
I think you'd use this is you think a post really needs to be seen. Maybe you will make it back on the post payout, but you can promote any post out there, I think.
This is more evolution of the Steemit platform. It's exciting to see new features.
People are already noticing some potential issues
